[markallen5]

Hello,
Since asking about buying an older scope on this forum, i've been offered what seems like a very good deal on a used pentax pf80ed. I had a look at/ through the scope and I couldn't see anything glaringly wrong, but the owner pointed out that there were marks on the glass on both the eyepiece and the other end, just slight wear and tear from years of use. Now I don't have the experience of looking through various scopes and I don't know how much these marks affect the clarity of the image viewed. As I said, I couldn't see anything obvious, but apart from being able to compare it, at the same time with a new scope of the same make and model( not possible) I imagine that at some point any scope , no matter how expensive when new, would be affected by wear and tear to the point that it would be better to leave it alone.
I would welcome any comments/ advice on what exactly to look for when trying to determine just how marks on the glass such as i've described affect the image.
Mark.

[etudiant]

The eye is pretty tolerant of glitches in the field of view, so small scrapes on the lenses usually don't matter at all. There can be exceptions, if you are looking towards a bright light (the sun for example), the scratches may add glare that detracts from the image.
Polishing marks are actually worse, imho, because they usually produce a larger area of degraded optical performance.
Do note that the eye piece is the primary component for setting image quality, so if that is good, you're golden.

[njlarsen]

For comparison: my Leica 10x42 bins (old model) have for years had some scratch marks on the objective end. A couple of years ago I ended up in an optics shop and could compare them directly to brand new Leicas, and there was surprisingly little difference, even with the existence of those marks.

My first scope was also a used one who served me for a number of years.

Niels

[mooreorless]

Hi Mark, The one down side is if you go to resale this scope, some people are very picky about any marks. As far as the eyepiece, these take most astro eyepieces. If you like it and there is a good price, buy it